docs: def _centered_edges(self):
          """
          A list of ``(xmin, xmax, ymin, ymax)`` tuples, one for each
          position, of the pixel edges after recentering the aperture at
          the origin.
  
          These pixel edges are used by the low-level `photutils.geometry`
          functions.
          """
  
          edges = []
          for position, bbox in zip(self.positions, self.bounding_boxes):
              xmin = bbox.ixmin - 0.5 - position[0]
              xmax = bbox.ixmax - 0.5 - position[0]
              ymin = bbox.iymin - 0.5 - position[1]
              ymax = bbox.iymax - 0.5 - position[1]
              edges.append((xmin, xmax, ymin, ymax))
  
          return edges